Field of the Invention
The present invention relates to an imaging device and an image display method, and more particularly to a technique of confirming focus.
Description of the Related Art
In a digital camera, an autofocus technique in which a phase difference detection method or a contrast detection method is used when focus is adjusted (focusing is performed) is known. On the other hand, a digital camera with a so-called a manual focus mode in which a user can manually adjust focus is also known.
A digital camera with the manual focus mode using a method in which contrast is visually checked by providing a reflex mirror so that focus can be adjusted while a photographed subject is checked is known.
Unfortunately, in the method in which contrast is visually checked, since the focus lens is moved back and forth around a focused point to find out a focused point, it is difficult to determine whether a subject is in focus in a state where the focus lens is not moved.
In a digital camera without a reflex mirror that has become wide spread in recent years, there is no method of checking a subject image while displaying phase difference because no reflex mirror is provided. As a result, focusing has to rely on the contrast detection method. In this case, however, it is impossible to display an image with contrast higher than that in resolution of a display device such as an LCD, so that a method of displaying the image by partially enlarging the image, or the like has to be used.
Thus, in recent years, a split image is displayed in a live view image (or called a through image) so that an operator can easily focus on a subject at the time of the manual focus mode. Here, the split image means that an image is split into top and bottom images each of which is displaced in a lateral direction when the subject is out of focus, corresponding to the amount of the out-of-focus, and each of which is not displaced in a lateral direction when the subject is in focus. A user operates a manual focus ring so that there is no displacement in the top and bottom images of the split image to focus on the subject (perform focusing).
Japanese Patent Application Laid-Open No. 2009-147665 (hereinafter referred to as PTL 1) describes an imaging device as an example of an imaging device that displays a split image. The imaging device creates a first image and a second image by applying photoelectric conversion to a first subject image and a second subject image, respectively, formed with pencils of light split by a pupil-split section in pencils of light from an imaging optical system, and creates the split image by using the first and second images as well as creates a third image by applying the photoelectric conversion to a third subject image formed with pencils of light that are not split by the pupil-split section. Then, the imaging device displays the third image in a display, as well as displays the split image created above in the third image, and also the imaging device is configured to add color information extracted from the third image to the split image.
On the other hand, unlike the split image, Japanese Patent Application Laid-Open No. 2005-229560 (hereinafter referred to as PTL 2) describes a stereoscopic image display method of alternately displaying right-eye images and left-eye images at high speed.